ACPI DSDT Investigation

There has been this problem with Acer Aspire 4530.
When the temperature of the GPU hits 99 degrees the fans don't seemed to turn on to cool it.
Instead the GPU throttle down but without the active cooling the throttling doesn't help instead it stays around 95-99 cycling back and forth.
Therefore I investigated the ACPI configuration of the laptop.
Using Phoenix BIOS editor I extracted the AML file contain compiled ACPI instruction.
The AML file is actually the DSDT Table which Windows load from the BIOS
Using Microsoft ASL Compiler I decompiled the AML file to a notepad readable format.
After checking with ACPI specification PDF documentation I discovered a flaw in the coding.
According to the ACPI documentation as shown below
_PSV is supposed to be the temperature which it safe to do passive cooling meaning fan can turn off.
However Acer programmed the _PSV value to be 0x63 (hex) which is actually 99 degrees in Decimal.
Which means when the laptop reaches 99 degrees it is safe to turn off the fan which led to this situation.
Therefore I modded the DSDT changed it to 45 degrees and overload the table to Windows Registry.
Now the fan no longer stop working when the temperature reaches high levels.

Here I share with you the patched DSDT (actually you can patch the BIOS but I prefer not to do this)

To use the DSDT install Microsoft ASL Compiler, v. 3.0.1 [646 KB] from this page.

Copy and paste the patched DSDT to "C:\Program Files\Microsoft ASL Compiler v3.0"
Then open a Command Prompt Windows with Admin Permission then type

cd "C:\Program Files\Microsoft ASL Compiler v3.0"
asl.exe /loadtable DSDT.AML

You should see "Table Overloading Succeeded".
Reboot.

I modified another value.
It is the return value for the THRM.
I modified the else condition to a higher hex value so the else condition will assume higher temperature.
I relink the link above to the newer file.

Hi guys sorry I promised there would be no changes to th Acer Aspire 4530 BIOS but I found some errors in the Acer Aspire 4530 DSDT code hence I had to recompile and replace the buggy DSDT code found originally in the Acer Aspire 4530 BIOS.

Here is an excerpt from the original buggy code.

I used IASL Compiler (Intel ASL Compiler) for this purpose as Microsoft ASL Compiler is non-standard(Doesn't guarantee Linux Compatibility), no optimization & buggy.

The new output after I corrected the DSDT:


As usual I always tested the new BIOS with my Aspire 4530 before releasing it so no worries.

Please refer here for the modified BIOS for Aspire 4530

**Note important!
I have removed the optimized DSDT as many seems to have issues with it.
If your Windows report error please flash from DOS (Read Instructions) because DOS doesn't require ACPI so it should be possible.

(Includes Win7 SLIC, Undervolted GPU & Corrected DSDT code)
I noticed things like Brightness Display during unplugging of Adapter and Battery is solved with this DSDT Code Correction.

Some Interesting Modding Ideas

I modded my Aspire 4530 AGAIN to control resultant temperature.
Below are some ideas and pictures.


Another mod idea

This time a black anodized Aluminium heat sink (Can be found in any hardware store) is added to increase the mass.
I had to cut and file it to size.
On the plus side it had thermal adhesive tape under it which makes attaching it an easy task.

ACPI Problems in Windows 7

(Error1

: The embedded controller (EC) did not respond within the specified timeout period. This may indicate that there is an error in the EC hardware or firmware or that the BIOS is accessing the EC incorrectly. You should check with your computer manufacturer for an upgraded BIOS. In some situations, this error may cause the computer to function incorrectly.

Result of Error 1

The speed of processor 0 in group 0 is being limited by system firmware. The processor has been in this reduced performance state for 3 seconds since the last report.

What does this means?

It means ACPI has detected the temperature has exceeded the threshold in the PSVT method in the DSDT contained in the BIOS. Therefore ACPI will automatically throttle down the CPU to lower states so temperature will drop. Hopefully.

I revised the DSDT file need further testing to confirm if the newer DSDT fixes the issue(Note: For Aspire 4530 only other Computers need their own DSDT).

Crazy Stuff I Did To Lower The Temperature Of The Laptop

Here is the deal:
You have encounter high temperatures especially during gaming.
You contacted the Repair Centre.
They told you to update the BIOS (usually the fix include making the fan spin more often).
You have sent the laptop back and forth until you have given up.

Finally the warranty run out and you can only depend on yourself.

Below are the following mods you can do.

For me I did the following:

Note: Most steps require dismantling of the system it will help with expert supervision and googling and down loading of service manual to dismantle it.

• Throw away the thermal pad on the GPU and use Arctic Silver 5 instead

• Remove the original CPU thermal paste and use Arctic Silver 5 instead.

Arctic Cooling MX-2

Arctic Silver 5

• Remove and throw away the "air filter" below the Laptop bottom cover to allow better air flow (I decided to do this after realizing this is the only part you can feel that air actually goes into the laptop, hence obstructing it restricts air flow hence remove it)

• Sand the surface of heatsink which comes into contact with the GPU or CPU chip, using FINE SILICON CARBIDE PAPER
  

• Sharpen the edges of the air vent casing (I got this inspiration by observing other Acer Aspire Laptop (Aspire 4935G) models, I noticed their vent size is gigantic compared to the vent size of this particular model hence it could be one of the gaming overheating factors. The new Acer Aspire 4736ZG Series Air Vents actually have even bigger holes than 4935G!)

Original (Top view)

Modified (Shave the vent corners)(Top view)

Actually the best cutting should be a wing shape pointing into the chassis.

The smaller the air drag the better.

Wikipedia

Not sure how much of this helps

But now my gaming temperatures fall below 90 degrees (around 85) and my idle temperature falls below 60 degrees (around 55) for the GPU.

Check out my recently modded laptop thermal exhaust:

Compare it to your original Aspire 4530 exhaust spot any difference?
Originally it has 16 dividers I cut out 8 of them so it looks like this.

5) I added Aluminium tape to bridge the laptop bottom chassis which is made out of metal to the heatsink.

Aluminium Tape

How I did it.

I rolled and flatten out one piece of Aluminium Tape to thicken it made sure it stucked in between the two interface without falling off (but not too tight).

Then I stick a tape over the heatsink and the chassis for better conduction.

The lowest temperature is now under 55 degrees hence it pretty much works.

6) UnderVolt the AMD Processor

7) Set the Graphics Mode to performance.

Harddisk Temperature on Aspire 4530

HWMonitor currently does not detect Harddisk Temperature.

However HWiNFO32 does.

Here is a screenshot.

Result of Changing Thermal Paste

(Temperatures at idle)

This is the new temperature reading after I changed the thermal paste.

Notice the new low reading especially on the GPU.

The reason is because Acer uses a thermal pad to conduct heat away from the GPU which is pretty inefficient.

After I changed the thermal pad and the original thermal paste, which is silicon based, the new temperatures are lower.

Originally the Processor Temperature is 60-70degrees.

Now it is 50-60 degrees at normal load 40-50 at idle.

Original the GPU is nearly 70 degrees now it is nearly 60 degrees.

10 degrees difference that is a lot.

(Temperatures while Gaming)

The temperature for the GPU used to exceed 100 degrees when gaming as some of you have experienced

Now it even barely hits 90 degrees (With elevated platform to allow airflow).

Hence I recommend if you want to game, please replace the factory thermal paste with high quality ones like Arctic Silver 5 or MX-2 if you are able to get one.

Arctic Cooling MX-2 is better as it is non-conductive, no cure time required and easier to apply.

Dissembly Guide here.

Example of the thermal pad use to transfer heat from the GPU to heatsink

In the Acer Aspire 4530 Air enters the laptop through the bottom and exits through the rear so for better ventilation try to prop the laptop bottom on an elevated platform to improve thermal circulation.

Full Dissembly Guide here

HWMonitor

This is what HWMonitor looks like

It shows the temperature taken by the thermal sensors inside your computer

Usually you will have no use for however it can act as a diagnostic tool such as computer slow downs especally graphic cards during intense gaming.Above all else isn't it interesting to know how hot is your internal component running?

The software is from CPUID team at http://www.cpuid.com/

Things to note about this applet

1)Small in size

2)No install required to uninstall just delete it

The software is obtained from their website in 2 versions 32bit and 64 bit

32bit is for all standard Windows XP 32bit and Vista 32bit

64bit is for those 64bit Vista Edition there is also Windows XP 64 bit edition but you rarely come across it.

To know what operating system you are running simply right click "My Computer" and select "Properties"

http://www.cpuid.com/hwmonitor.php

Glossary

ACPI a power management technology implementation built into recent systems

AMD Turion X2 refer to the dual core AMD Processor core#0 and core#1

GPU refer to the graphic card temperature

While HDD refer to the Harddisk temperature obtained from SMART (Self-Monitoring, Analysis, and Reporting Technology)